Failed NOx Help?
Originally Posted by fuddyduddy121
I don't think the catalytic converter is there for NOx. It'* purpose is to reduce hydrocarbons, not NOx.
Most cars today are equipped with a three-way catalytic converter. The term Three-way refers to the three emissions it helps to reduce, carbon monoxide, hydrocarbons or volatile organic compounds (VOCs) and NOx molecules."
http://autorepair.about.com/cs/gener.../aa080401a.htm
The only question is how "today" is a '93? Thats the thing I hate about some manuals. Well sheit was this written in 1950?! Or was it in 2004 and they're being literal with 'today'. Do you know if which one we use? I'm kind of curious now, this was news to me.
I have a hard time believing the NOx reduction in a catalytic converter is very effective, effective NOx reduction usually only occurs at the source with lower combustion temperatures or lower residence time.
For effective NOx reduction in an exhaust stream using catalytic reduction, you really need some time of ammonia or urea injection. I still have difficulty blaming the cat for high NOx.
For effective NOx reduction in an exhaust stream using catalytic reduction, you really need some time of ammonia or urea injection. I still have difficulty blaming the cat for high NOx.
Yeah I doubt the cat would be his problem as I would expect to see everything high when failed. I'm not sure how much the cat reduces nox but aparently the chemical responsible for it is called Rhodium. More info avail: http://www.autoshop101.com/forms/h64.pdf
Haven't read it all but looks very informative.
Haven't read it all but looks very informative.
not sure if your EGR valve is digital, neg. back pressure or what but if its neg. back pressure (has the solenoid which hooks via vac. line to the bulby- gold thing) you should also check to see if the valve itself opens or not.. to make it open, just unplug one of the vacuum lines at the Solenoid ( i remember it being the vacuum hose that does NOT go from solenoid to valve) and just plug it with your finger and that makes the valve open and thus the car starts sputtering and coming to a stall... if your valve is locked shut it shouldn't open at all..
on mine, the valve was ok but the solenoid was bad :/
Miek Diaz
on mine, the valve was ok but the solenoid was bad :/
Miek Diaz
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From: Edison, NJ

Just want to finish up the thread so when people search they see what I did.
After replacing the PCV valve, cause in NJ they want a reciept showing you actually did something to car, I drove home from work for like half an hour and went through again, just letting it get hot, what a diference it made
Standard 853, Failed without car warm 1115, With fully warmed car, 91! Pass
HC went up 2pnts to 6, but was well below the 114 standard. Thanks for all the help. Now I can change the O2 sensor when I get around to getting the socket.
After replacing the PCV valve, cause in NJ they want a reciept showing you actually did something to car, I drove home from work for like half an hour and went through again, just letting it get hot, what a diference it made
Standard 853, Failed without car warm 1115, With fully warmed car, 91! Pass
HC went up 2pnts to 6, but was well below the 114 standard. Thanks for all the help. Now I can change the O2 sensor when I get around to getting the socket.
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